SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b475693945f6e172d3ff46892a89cf0954152d603fd38e90a9bdf96c720fe9d0' 
  AND token = 'FAJhx3FkcDcvq5hnSmXh4G6zpN0LUsBHa8WloeLZpsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}